Substrate-mediated sub-diffraction guiding of optical signals through a linear chain of metal nanoparticles: Polarization dependence and the role of the dispersion relation

We theoretically investigate the efficiency of transmitting optical signals through a linear chain consisting of identical and equidistantly spaced silver nanoparticles in the presence of a reflecting substrate. The energy exchange between surface plasmon polaritons of the chain and the substrate can give rise to an increased transmission. We focus on the effects of the polarization of the excitation and the role of the dispersion relation of the collective chain-substrate modes.